Comparing the “repl” and “repl*” columns, we observe that combining scores from the retriever yields modest gains across all conditions.
These gains are significant for four out of the six conditions, which suggests that retriever scores contribute to improving effectiveness.
Comparing the “GAR” and “repl” columns, we also observe modest gains when adopting the answer span selection technique of [1]}.
These gains are significant for all except one condition.
Comparing the “GAR” and “GAR*” columns, we find that in all cases, incorporating retriever scores significantly increases effectiveness.
